This invention relates to safety razors for wet shaving and, more specifically, to powered wet shaving systems with disposable blade cartridges.
Some wet shaving razors have been provided with battery-powered devices such as motors for vibrating a shaving cartridge. One such vibrating wet shaving razor is that sold by The Gillette Company under the trade name the Gillette Fusion™ razor. This razor features a battery disposed in a chamber within its handle, and a motor coupled to the distal tip, on which is mounted a replaceable cartridge, and electronic controls for razor operation.
Some wet shaving razors attempt to track blade wear and indicate when the cartridge should be replaced. In the course of shaving hundreds of hairs on a daily basis, the blades of a shaving cartridge inevitably grow duller. This dullness is difficult to detect by visual inspection. In too many cases, by the time a user realizes that a blade is too dull to use, he has already begun what will be an unpleasant shaving experience.
Some wet shaving razors have mechanical shave counters for manual counting of each shave. Other wet shaving razors have electronic shave counters that track shaving action (e.g., exposing the razor to moisture, contacting skin with blades, moving or applying forces on the blades or cartridge, gripping the handle, activating a vibration source) as a proxy for blade wear. Some electronic shave counters count discrete shaving uses (e.g., activation of a vibration source) while others count time that the razor is active (e.g., vibrating) or the time that the razor spends shaving (e.g., detecting skin contact or cartridge movement). Some wet shaving razors estimate a remaining cartridge life based on the tracked shaving use.
Some wet shaving razors have an indicator to inform a user that the cartridge should be replaced. Some indicators are numeric displays, either mechanical or electronic, showing a count of accumulated shaving uses. The user must learn by experience what number of shaves to expect from a cartridge and must remember to change the cartridge at that number of shaves. Some indicators abruptly inform the user that the cartridge should be replaced, such as by changing vibration (e.g., changing vibration frequency, vibrating in a pattern), emitting an audible sound, or activating a light source, without a warning that the suggested replacement is approaching.
One wet shaving razor includes an indicator having a series of seven LEDs. When the razor senses that a cartridge has been attached, the entire series is lit to indicate the cartridge has all of a predetermined initial shaving time remaining. As the razor is used, the initial shaving time is counted down and LEDs are extinguished in proportional sharp steps. When all the LEDs are extinguished, no shaving time remains and the cartridge should be replaced. Indicators with more LEDs tend to consume more power and cost more than indicators with fewer LEDs.
Mixing colors of light, also called additive color mixing, is known. Some applications of additive color mixing, such as signs, ornamental displays, and decorative lighting, for example, mix light of two or more LEDs to create light colors different than either LED.
Using materials that change electrical properties in response to a change in applied forces in switches are known.
A need exists to overcome the shortcomings aforementioned.